Radial centering device for high speed transmission couplings

ABSTRACT

A radial centering device for high speed transmission couplings of the type having a ball-and-socket joint. The ball is disposed at the end of an extension of a first shaft and the socket is disposed at the end of an extension of a second shaft. A first bearing is interposed between the needle or roller and the extension of the first shaft and a second bearing is interposed between the socket and the extension of the second shaft. The ball sliding relative to the shaft on during a change of the operating between the two shafts.

Unite States Patent 1191 Drain 1 Feb. 19, 1974 [54] RADIAL CENTERINGDEVICE FOR HIGH 2,206,291 7/1940 Nelson 64/21 PE D R S O COUPLINGS3,621,674 11/1971 Ulics et a1. 3,628,290 12/1971 Wilson 64/21 [75]Inventor: Michel Orain, Conflans Sainte H0n rine France Assignee:Societe Anonyme: Glaenzer p 698,945 11/1940 Gen'nany 64/21 Poissy,France Primary Examiner-Ben amin W. Wyche [22] Flled: 1971 AssistantExaminer-Randall Heald [21] APP] NOJ 198,734 Attorney, Agent, orFirmBaldwin, Wight & Brown [30] Foreign Application Priority Data [57]ABSTRACT Nov. 24, 1970 France 7042175 A radial Centering device for highSpeed transmission couplings of the type having a ball-and-socket joint.52 U.S. c1. 64/7, 64/8, 64/11 B, The ball is disposed at the end of anextension of a 237/ 7 first shaft and the socket is disposed at the endof an 51 1m. .01. F1611 3/16 extension of a Second Shaft A first bearingis inter- 5 1 Field f Search 64/8, 7 11 B, 21; 237 7 posed between theneedle or roller and the extension 2 7 3 3 7 of the first shaft and asecond bearing is interposed be- I tween the socket and the extension ofthe second 56 References Cited shaft. The ball sliding relative to theshaft on during a Change Of the Operating between the two Shafts.3,162,471 12/1964 Mazziotti 287/87 7 Claims, 2 Drawing Figures RADIALCENTERING DEVICE FOR HIGH SPEED TRANSMISSION COUPLINGS The presentinvention concerns a mechanical device for ensuring a fixed point ofconvergence of the axes of two shafts having a fixed or variable angletherebetween and connected together by a homokinetic transmissioncoupling which itself is not centred, such a double universal joint, thedevice being particularly suited for the transmission of high rotationalspeeds.

It is known that homokinetic universal joints commonly used in theautomobile industry are formed of the combination of two simpleuniversal joints held in phase and a ball-and-socket connecting assemblyfor the two shafts such that the two universal joints operate at thesame angle. Thus connected up, the homokinetic defects of each universaljoint is canceled out by the other.

But for applications in which a high speed is required, the oscillatorymovement of the ball-and-socket joint is also very great and as the loadexerted on the ball-andsocket joint is significant, heating up of theball-andsocket joint and an insufficient industrial life have beenobserved.

Indeed, if N is the rotational speed of the coupling, r the radius ofthe ball and a the operating angle of the coupling, the maximum slidingspeed of the ball is:

v 2Nr sin 62/2 The present invention consists in a radial centringdevice in a homokinetic coupling operating at high speeds foreliminating the sliding of the central ball at a predetermined operatingangle, the sliding movement of the ball only occurs during a change ofthe angle between the shafts to be connected.

The radial centring device comprises a ball-andsocket joint connectingthe ends of extensions on shafts to be connected, the pivoting iseffected in ball bearings, roller bearings or needle bearings interposedbetween the socket of the ball-and-socket joint and the extension of thecorresponding shaft and between the ball of the ball-and-socket jointand the extension of the second shaft.

In an embodiment in which the rotational driving of the driven shaft bythe driving shaft is ensured by a metal or plastics bellows and in whicheach of the shafts includes an extension one of which ending in a balland the other in a socket for the ball, the ball being mounted by meansof a roller bearing at the end of the first shaft whereas thesphericalsocket for the ball is constituted by the inner race of a ball bearing,the outer race of which being fixed to the socket at the end of thesecond shaft.

According to an alternative embodiment in which the rotational drivingof a shaft by a second shaft is ensured by a double universal joint, theradial centring device comprises a ball fixed to a short shaft turningin two roller bearings housed in a bore formed in one of the two arms ofthe body of one of the universal joints whereas the spherical socket forreceiving the ball is fixed to the other short shaft turning in ballbearings and a roller bearing housed in a bore formed in one of the armsof the body of the other universal joint.

The invention is described in greater detail hereinafter with referenceto the accompanying drawing, in which FIG. 1 shows a longitudinalsection of a homokinetic coupling driven by a bellows; and

FIG. 2 shows a longitudinal section of a homokinetic coupling driven bya double universal joint.

FIG. 1 shows an embodiment of the invention in which the radial centringdevice couples two shafts 1 and 2 with a coupling bellows 3, the shaftshaving extensions la and 2a extending towards the interior of thecoupling.

The extension 2a includes a bore 4 in which a ball bearing 5 is fittedhaving an inner race 6 which is spherically bored and pivots about aball 7 which may be of self-lubricating metal or plastics material.

The ball 7 has a needle bearing 8 mounted for rotation on the journal 9forming the end of the extension la of the shaft 1. v

When the shafts l and 2 of the coupling rotate at the angle atransmitting a torque C, the pivoted connection is subject to asignificant radial load perpendicular to the plane of the angle ofcoupling, i.e. perpendicular to the plane of FIG. 1 and exerted at thecentre P of the pivoted connection.

The result is that the combination comprising the inner race 6 of theball bearing, the ball 7 and the outer race of the needle bearing 8 arefixed with respect to the two shafts, in other words there is no slidingmovement of the ball relative to the socket during the rotation of theshafts of the coupling at an angle. The only movement causing thesliding of the ball 7 in the spherical bore of the race 6 is the changeof the angle 0:.

Thus, the heating and the wear of the pivoted balland-socket joint areavoided. Further, under these conditions the ball may be produced ofresilient materials such as plastics or elastom eric materials whichwhile eliminating play by a tight assembly enable the reduction of thetransmission of high frequency vibrations which would otherwise passfrom one shaft to the other across the coupling.

FIG. 2 shows another embodiment of the radial centring device used on ahigh speed homokinetic coupling with a double universal joint.

In this embodiment the shafts 1] and 12 are integral with bodies 13 and14 respectively of two classic universal joints.

Cross pins 15 and 16 are placed in the bodies 13 and 114, the journalsare in the conventional manner each provided with a bearing fitted inthe bores in the bodies 13 and 14 and in a coupling sleeve 17 connectingthe two bodies 13 and 14.

Each of the bodies 13 and 14 have hollow extensions 113a and 14a alignedwith the shafts ill and 12 respectively.

In the bore in the extension 13a two needle or roller bearings 18 and 19are seated in which a short shaft 20 ending in a ball 21 may rotate.

in the bore in the extension 14a a roller bearing 22 and a ball bearing23 are seated in which a short shaft 24 may rotate having at its end asocket 25 with a spherical cavity in which the ball 21 may oscillate.

A resilient sheath 26 connecting the shaft 20 to the shaft 24 enables alubricant to be maintained in the ball-and-socket joint.

It should be noted that the female extensions 13a and 14a may be maleextensions in order to guide from within the female end of the ball andthe socket bearmgs.

It is quickly realized that roller bearings, needle bearings or ballbearings are off set in relation to the balland-socket joint and thatthis construction reduces bulkiness near the ball.

The embodiments described hereinabove are not intended to be limiting;the invention is also applicable to combinations of couplings andball-and-socket joints, the two systems capable of being associated.

The invention is applicable to all mechanical arts and more particularlyto automotive arts.

What we claim is:

1. A radial centring device for high speed transmission shaft couplingsof the type having a ball-andsocket joint comprising an extension oneach of the shafts to be coupled, a ball being disposed at the end ofthe extension on a first shaft and a socket being disposed at the end ofan extension on a second shaft, and a first bearing being interposedbetween said ball and said extension on the first shaft and a secondbearing being interposed between said socket and said extension on thesecond shaft, at least one of said bearings being a ball bearing.

2. A radial centring device for high speed transmission shaft couplingsof the type having a ball-andsocket joint comprising an extension oneach of the shafts to be coupled, a ball being disposed at the end ofthe extension on a first shaft and a socket being disposed at the end ofan extension on a second shaft, and a first bearing being interposedbetween said ball and said extension on the first shaft and a secondbearing being interposed between said socket and said extension on thesecond shaft, a bellows operatively connected between the first andsecond shafts for ensuring the rotation between said shafts, and aspherical socket for the ball being formed in an inner race ofa ballbearing mounted in a support case at the end of the extension of thesecond shaft, the outer race of the ball bearing being fixed to thesupport case, and the ball being mounted on a bearing on the firstshaft.

3. A radial centring device for high speed transmission shaft couplingsof the type having a ball-andsocket joint comprising an extension oneach of the shafts to be coupled, a ball being disposed at the end ofthe extension on a first shaft and a socket being disposed at the end ofan extension on a second shaft, and a first bearing being interposedbetween said ball and said extension on the first shaft and a secondbearing being interposed between said socket and said extension on thesecond shaft, the ball being formed integral with a first short shaft,said first short shaft being received in a sleeve in the body of a firstuniversal joint forming an extension of the first shaft; and the socketbeing formed integral with a second short shaft, said second short shaftbeing received in a sleeve in the body of a second universal jointforming an extension of the second shaft.

4. A device according to claim 3, wherein two roller bearings areinterposed between the first short shaft and said sleeve in the body ofthe first universal joint, and wherein a ball bearing and a rollerbearing are interposed between said second short shaft and said sleevein the body of the second universal joint.

5. A radial centring device for high speed transmission shaft couplingsof the type having a ball-andsocket joint comprising an extension oneach of the shafts to be coupled, a ball being disposed at the end ofthe extension on a first shaft and a socket being disposed at the end ofan extension on a second shaft, and a first bearing being interposedbetween saidv ball and said extension on the first shaft and a secondbearing being interposed between said socket and said extension on thesecond shaft, said ball being formed of a resilient material.

6. A radial centring device for high speed transmission shaft couplingsof the type having a ball-andsocket joint comprising an extension oneach-of the shafts to be coupled, a ball being disposed at the end ofthe extension on a first shaft and a socket being disposed at the end ofan extension on a second shaft, and a first bearing being interposedbetween said ball and said extension on the first shaft and a secondbearing being interposed between said socket and said extension on thesecond shaft, said ball being formed of plastic.

7. In a radial centering device for high speed transmission shaftcoupling of the type having a ball-andsocket joint and including anextension on each of the shafts to be coupled with there being a ball atthe end of an extension of a first shaft and a cooperating socket at theend of an extension of a second shaft; the improvement residing inmounting means mounting said ball and socket for limited relativemovement during the operation of said coupling, said mounting meansincluding first bearing means mounting said ball for relative rotarymovement with respect to said extension of said first shaft and secondbearing means mounting said socket for relative rotary movement withrespect to said extension of said second shaft, and at least one of saidbearing means being a ball bearing.

1. A radial centring device for high speed transmission shaft couplingsof the type having a ball-and-socket joint comprising an extension oneach of the shafts to be coupled, a ball being disposed at the end ofthe extension on a first shaft and a socket being disposed at the end ofan extension on a second shaft, and a first bearing being interposedbetween said ball and said extension on the first shaft and a secondbearing being interposed between said socket and said extension on thesecond shaft, at least one of said bearings being a ball bearing.
 2. Aradial centring device for high speed transmission shaft couplings ofthe type having a ball-and-socket joint comprising an extension on eachof the shafts to be coupled, a ball being disposed at the end of theextension on a first shaft and a socket being disposed at the end of anextension on a second shaft, and a first bearing being interposedbetween said ball and said extension on the first shaft and a secondbearing being interposed between said socket and said extension on thesecond shaft, a bellows operatively connected between the first andsecond shafts for ensuring the rotation between said shafts, and aspherical socket for the ball being formed in an inner race of a ballbearing mounted in a support case at the end of the extension of thesecond shaft, the outer race of the ball bearing being fixed to thesupport case, and the ball being mounted on a bearing on the firstshaft.
 3. A radial centring device for high speed transmission shaftcouplings of the type having a ball-and-socket joint comprising anextension on each of the shafts to be coupled, a ball being disposed atthe end of the extension on a first shaft and a socket being disposed atthe end of an extension on a second shaft, and a first bearing beinginterposed between said ball and said extension on the first shaft and asecond bearing being interposed between said socket and said extensionon the second shaft, the ball being formed integral with a first shortshaft, said first short shaft being received in a sleeve in the body ofa first universal joint forming an extension of the first shaft; and thesocket being formed integral with a second short shaft, said secondshort shaft being received in a sleeve in the body of a second universaljoint forming an extension of the second shaft.
 4. A device according toclaim 3, wherein two roller bearings are interposed between the firstshort shaft and said sleeve in the body of the first universal joint,and wherein a ball bearing and a roller bearing are interposed betweensaid second short shaft and said sleeve in the body of the seconduniversal joint.
 5. A radial centring device for high speed transmissionshaft couplings of the type having a ball-and-socket joint comprising anextension on each of the shafts to be coupled, a ball being disposed atthe end of the extension on a first shaft and a socket being disposed atthe end of an extension on a second shaft, and a first bearing beinginterposed between said ball and said extension on the first shaft and asecond bearing being interposed between said socket and said extensionon the second shaft, said ball being formed of a resilient material. 6.A radial centring device for high speed transmission shaft couplings ofthe type having a ball-and-socket joint comprising an extension on eachof the shafts to be coupled, a ball being disposed at the end of theextension on a first shaft and a socket being disposed at the end of anextension on a second shaft, and a first bearing being interposedbetween said ball and said extension on the first shaft and a secondbearing being interposed between said socket and said extension on thesecond shaft, said ball being formed of plastic.
 7. In a radialcentering device for high speed transmission shaft coupling of the typehaving a ball-and-socket joint and inCluding an extension on each of theshafts to be coupled with there being a ball at the end of an extensionof a first shaft and a cooperating socket at the end of an extension ofa second shaft; the improvement residing in mounting means mounting saidball and socket for limited relative movement during the operation ofsaid coupling, said mounting means including first bearing meansmounting said ball for relative rotary movement with respect to saidextension of said first shaft and second bearing means mounting saidsocket for relative rotary movement with respect to said extension ofsaid second shaft, and at least one of said bearing means being a ballbearing.